Start with your device volume low. Very low tones may be inaudible on phone or laptop speakers; very high tones can be uncomfortable on headphones.
What does 20,000 Hz sound like?
20,000 Hz is a ultrasound frequency. It is ultrasound: above the upper limit of human hearing, although many animals – dogs, cats, bats, dolphins and rodents – can hear it.
A 20,000 Hz sound wave completes 20,000 cycles every second, so one cycle lasts 50 µs. In air at 20 °C, where sound travels at about 343 m/s, each wave is 1.7 cm (0.68 in) long; in water it stretches to 7.4 cm because sound moves about 4.3 times faster there.
Hearing at these frequencies declines steadily with age (presbycusis) and with noise exposure. If you cannot hear this tone, check that your headphones can reproduce it before drawing conclusions – and try our hearing test for a playful estimate.
Wavelength of 20,000 Hz in different materials
| Medium | Speed of sound | Wavelength |
|---|---|---|
| Air (20 °C) | 343 m/s | 1.7 cm |
| Fresh water | 1,481 m/s | 7.4 cm |
| Seawater | 1,500 m/s | 7.5 cm |
| Helium | 1,007 m/s | 5.0 cm |
| Steel | 5,960 m/s | 29.8 cm |
| Glass | 5,640 m/s | 28.2 cm |
Harmonics and octaves
Real instruments playing 20,000 Hz also produce harmonics at whole-number multiples of the fundamental. Their relative strength gives each instrument its timbre.
Which animals can hear 20,000 Hz?
Can hear it
Humans, Dogs, Cats, Horses, Cows, Sheep, Pigs, Goats, Rabbits, Rats, Mice, Gerbils, Guinea pigs, Hedgehogs, Raccoons, Ferrets, Opossums, Chinchillas, Bats, Beluga whales, Bottlenose dolphins, Greater wax moths
Cannot hear it
Elephants, Chickens, Canaries, Budgerigars (parakeets), Cockatiels, Owls, Bullfrogs, Tree frogs, Goldfish, Catfish, Tuna
Frequently asked questions
What does 20,000 Hz sound like?
It is ultrasound: above the upper limit of human hearing, although many animals – dogs, cats, bats, dolphins and rodents – can hear it.
Can humans hear 20,000 Hz?
Yes. 20,000 Hz is inside the typical human hearing range of 20 Hz to 20 kHz, although many adults lose sensitivity above about 15 kHz.
What musical note is 20,000 Hz?
20,000 Hz is outside the range normally used for musical notes.
What is the wavelength of 20,000 Hz?
About 1.7 cm in air at 20 °C and 7.4 cm in water.
Can dogs hear 20,000 Hz?
Yes – dogs hear roughly 67 Hz to 45,000 Hz.